The Bute Energy/Green GEN Towy-Usk Project Proposal

In early spring 2023 Green GEN Cymru, part of Bute Energy, announced their Towy-Usk electrictity line proposal. Initial public consultations commenced in March. The following is taken from the original Green GEN Towy Usk project website, explaining that proposal.

The Green GEN Towy Usk proposal is for a new 132kV (132,000- volt) double-circuit overhead line, supported on steel pylons, between a substation on the Nant Mithil Energy Park in the Radnor Forest area and a new substation, to be developed by National Grid, on the existing 400kV (400,000-volt) transmission line near Llandyfaelog, between Carmarthen and Pont Abraham.

When drawing up our plans, we compared the environmental, technical and cost implications of 11 potential connection options. Following this work, connecting the Nant Mithil Energy Park to the national grid in the Carmarthen area was determined to be the most appropriate solution to take forward for more detailed routeing studies and consultation.

The new 132kV overhead line will be carried on steel lattice pylons. We need to use steel pylons because there will be two circuits (three sets of wires on each side of the pylons), carrying more power than can be carried safely on a single line of wooden poles. Each pylon will have three arms on each side, and each arm will carry a set of wires – known as conductors.

The standard height for a 132kv pylon is 27m. The average distance between pylons, or ‘span length’, is approximately 250m. Exact pylon heights and span lengths can be increased or decreased depending on the terrain they cross, or obstacles like streams and rivers.

Working with our environmental consultants, we identified corridors of land through which an overhead line route could be installed, looking at how each might affect local communities, the landscape, local views, biodiversity, forestry and cultural heritage, floor risk and other land uses. 

In spring 2024 Green GEN Cymru announced important revisions to their proposal with a second round of public consultation from mid March. The following update is taken from their website.

Our revised proposals

We carefully considered all feedback received in our first round of consultation, alongside further environmental and technical assessments. We have now revised our plans and have identified a draft route alignment which shows where the infrastructure might go.

We have made a number of changes to our proposals to include:

  • a single-circuit overhead line supported on wood poles between Nant Mithil Energy Park and a new switching substation at the foot of Aberedw Hill;
  • a section of underground cable where the route crosses the River Towy near Llanarthney, and;
  • some alterations to the route in other places. 

The main route change affects the section between Llandovery and Llandeilo, with the line now running predominantly to the north of the A40. Apart from the undergrounded and wood-pole sections the other route changes are relatively minor. However, the entire route is defined in more detail and includes positions of individual pylons.

The revised route can be found on their website - Green GEN interactive map (opens in new tab) or may be viewed on our own interactive map.


The Problem

We fully support renewable energy, but believe any development must respect the environment, not damage it.

The cables and their pylons that Green GEN Cymru/Bute Energy are proposing, would run through some of the most historic and environmentally sensitive landscapes in Wales. We want to preserve our beautiful rural area for future generations and not allow it to be damaged and devalued for profit.


photo from In Your Area


This is not a project ‘for Wales’ and should not be presented as such. The Green GEN Cymru/Bute Energy literature justifying the pylon line from Nant Mithil to Llandyfaelog, suggests that this is a green project for Wales. However, the electricity generated would be fed into the UK National Grid so it is not a case of the energy being produced in Wales for the benefit of Wales. Wales already generates approximately twice as much electricity as it consumes.

The Green GEN transmision line projects, Towy-Usk and three others, are only to provide connections for the ambitious and potentially extemely profitable energy park projects of its parent company Bute Energy. Taking commercial advantage of the government's Net Zero agenda, this is a Gold Rush that will industrialise the beautiful landscapes of rural Wales.

So, we say NO to the Green GEN Cymru/Bute Energy proposals and ask others to join us in our fight to stop our countryside from being blighted and irreversibly damaged.

The Solution?

Without question the best outcome is complete refusal of this electricity line proposal, and others similar, together with abandoning the plans for the huge wind farms that require them. There are better and more environmentally sensitive options for future energy.

If we absolutely must have any new power lines then they should be installed underground, to minimise visual pollution. There are modern methods of laying underground services that are less destructive and generally lower cost than traditional trench digging. There should also be consideration for moving existing overhead lines underground, as is happening in other parts of Great Britain.

The need for renewable energy is undeniable, but giant wind turbines on the hills with their associated long distance connection lines is not the answer. We need power generation local to where it's needed. We should promote smaller scale community based schemes and consider largely untapped opportunities such as greater use of rooftop solar. These may be supplimented by well engineered and located off-shore sources. Above all we must all learn to consume less power, whether directly or indirectly, and not demand ever more from the planet's resources!

Further information

Our original reponse letters following the initial consultation

Renewable Energy Options - Pros and Cons

Electricity Supply Facts (Video modules)

Downloadable documents and external web links